1. Field of the Invention
The invention concerns an apparatus for automatically severing poultry legs in the area of the knee joint, the poultry legs being separated from the body and respectively comprising an inside leg portion or thigh and a lower leg portion (shank), also, in the case of poultry and the like, termed drumstick, the apparatus comprising holders revolving in an essentially horizontal plane for holding the legs suspended at the distal end of the drumstick, means for supporting the legs, guiding means for guiding and aligning the legs and cutting means for severing the legs.
When processing poultry legs in this manner it is essential that the severing of the thigh from the drumstick occurs in such a manner that splintering or shaving off of the bone is avoided to ensure high quality of the resulting cuts.
2. Prior Art
EP 0 381 093 discloses an apparatus for cutting up a poultry body which is equipped with a station for dividing poultry legs which have been separated from the body in a previous operation. The legs are suspended from the ankle joint and conveyed around a support disc which has recesses arranged around its circumference for receiving the legs and is driven synchronously with the hanging conveyor. A knife for severing the legs is arranged at the periphery of the disc.
With this apparatus it is intended that the components of the knee joint be pulled apart by shear forces so that the leg can be severed cleanly between the ball and socket of the joint. A disadvantage is that such an operation can be achieved only when the apparatus is precisely adapted to the length of the drumstick of the leg being processed.
A further apparatus adapted to cut through the legs of animals, and specifically poultry, near the knee joint is disclosed in EP 0 442 554. In this apparatus the legs are conveyed while suspended from the ankle joint and positioned with respect to a cutting device by elements which act on the knee cap before the cutting device severs the leg from the rear of the naturally bent knee. In order that the legs may be correctly positioned prior to the cutting operation several positioning elements are required which are individually controlled to act on the poultry leg in a strict order. The resulting apparatus is consequently very complex and costly to manufacture and to maintain.